1. Field of the Invention
The present invention relates to clutch releasing devices for clutch assemblies adapted for use on automotive vehicles, and more particularly to clutch releasing devices for positively releasing a clutch disc assembly from a flywheel of vehicles.
2. Description of the Prior Art
It is desirable in clutch assemblies that disengagement of the clutch be accomplished quickly without any drag. However, in conventional clutch assemblies, a clutch disc assembly is adapted to be released from the flywheel only by vibration of the automotive engine and the like. Consequently, the friction facings of the clutch disc assembly are likely to adhere to the flywheel even when a pressure plate is completely disengaged, the friction facings of the clutch disc assembly being compressed by the flywheel and the pressure plate during clutch engagement.
In order to improve the above drawback, clutch releasing devices for positively releasing the clutch disc from the flywheel have been proposed. However, in some of them, the position of the clutch disc assembly released from the flywheel is constant, so that the clutch disc assembly is in turn likely to adhere to the pressure plate upon clutch disengagement since the position of the pressure plate is displaced toward the clutch disc assembly in accordance with the wear of the friction facings so as to maintain the clutch pedal stroke as constant. In another type of clutch releasing device wherein the position of the clutch disc assembly released from the flywheel is automatically displaced toward the flywheel in accordance with the wear of the friction facings, the clutch releasing device acts upon the wear of the friction facings through the axial movement of a hub of the clutch disc assembly. However, the hub of the clutch disc assembly is normally urged to move toward the flywheel by a transmission input shaft during assembly of the clutch assembly, so that the clutch releasing device fails to release the clutch disc from the flywheel.